The next step was to weld up the panel back in. FJ60 sheet metal is thinner than older FJ40 sheet metal, and it took a couple of blasted through holes to get the welder dialed in. I ended up using the lowest voltage setting.
It was also tricky to make sure I didn't start any fires on the inside of the cavity - it sits right under the fuel filler neck and all the separator hoses!
There was quite a bit of metal missing from the right side of the panel.